The invention concerns a method of producing an aerated confectionery foam from a sugar solution and a foaming-promoter solution batch by batch with a boiler and a beater, wherein the sugar solution is boiled in the boiler and transferred to the beater and the aerated confectionery foam is created out of the foaming promoter and the boiled sugar solution and pressure-extracted from the beater. A sugar solution is a solution of sugar, glucose syrup, and other ingredients in water. Sugarless ingredients can also be employed as sugar solutions. A foaming-promoter solution is also a solution in water of such foaming promoters as egg white, gelatine, etc. The foaming-promoter solution can also contain some sugar solution or similar material. The same solution may include colorants, flavorings, etc.
A method of this type is known from German Patent 3 528 637. The boiling process can be carried out in the boiler under atmospheric pressure because the processing in the beater is carried out in a vacuum. The sugar solution, boiled under atmospheric pressure, is transferred to the beater and processed in a vacuum to reduce it to the requisite residual-water content and to a temperature desirable for future processing. Once the vacuum has been lifted, the foaming-promoter solution is added to the sugar solution in the beater. The two masses are then beaten together under atmospheric pressure or in a vacuum. Increased pressure is preferably introduced during the beating process in order to provide as much air as possible for working into the confectionery foam that forms during the beating process. The purpose of increasing the pressure is to induce the mass to expand later when it is extracted from the beater to obtain masses with a low specific gravity. The individual bubbles of air that are worked into the mass will of course expand in accordance with the drop in pressure. The drawback to this approach is that the foaming-promoter solution comes into contact with the hot sugar solution before the beating stage and coagulates prematurely, so that its contribution to producing the foam is reduced. The foaming capacity of the foaming-promoter solution is accordingly incompletely exploited.
Creating a preliminary foam in a beater without any sugar solution present is also known. The foaming-promoter solution is usually beaten under atmospheric pressure. The sugar solution can be boiled in the boiler under atmospheric pressure, subject to increased pressure, or in a vacuum. The boiled sugar solution is then added to the preliminary foam in the beater, under atmospheric pressure for practical purposes. The preliminary foam and the sugar solution are then mixed together and beaten again, with increased pressure being multiply employed with the objective of ensuring enough air during the beating process to expand the confectionery foam as it is extracted from the beater and hence obtaining the associated low specific gravity. The potentially desirable vacuum treatment of the confectionery foam after beating that would be expected to reduce its residual moisture content is impossible because the expansion of the mass that would then occur inside the beater would force some of it into the line and into the vacuum generator.
The bubbles worked into the mass and full of gas, preferably air, in all known methods of producing aerated confectionery foams are considered too large for many purposes. Especially when the aerated confectionery foam is released from increased to atmospheric pressure, the volume of each individual bubble can only be increased.